Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2021 August 31
The picture shows the full moon in high resolution and exaggerated colours.
Please see the explanation for more detailed information.

A Blue Moon in Exaggerated Colours
Image Credit & Copyright: Robert Fedez

Explanation: The Moon is normally seen in subtle shades of grey or gold. But small, measurable colour differences have been greatly exaggerated to make this telescopic, multicoloured, moonscape captured during the Moon's full phase. The different colours are recognized to correspond to real differences in the chemical makeup of the lunar surface. Blue hues reveal titanium rich areas while orange and purple colours show regions relatively poor in titanium and iron. The familiar Sea of Tranquility, or Mare Tranquillitatis, is the blue area toward the upper right. White lines radiate across the orange-hued southern lunar highlands from 85-kilometre wide ray-crater Tycho at bottom right. The full moon that occurred earlier this month could be counted as a seasonal blue moon because it was, unusually, the third of four full moons to occur during northern summer (and hence southern winter). The featured 272-image composite demonstrates that the full Moon is always blue, but usually not blue enough in hue to ooh.

Almost Hyperspace: Random APOD Generator
Tomorrow's picture: galactic ghosts


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